“DTF machines print a solid white ink underbase beneath every active pixel, so any pixel that isn't fully transparent gets white”

Printify (Source 1) states the claim almost word for word, saying DTF machines print a solid white underbase under every non-transparent pixel. CADlink Digital Factory (Source 2), the RIP software that actually controls the white layer, shows this is a configurable setting rather than a fixed rule. Its Adaptive mode scales white density by pixel opacity, Coverage underbase uses less white under darker values, and Valid Pixel Tolerance skips errant pixels. Printify's simplification holds as a file-prep rule of thumb, but 'solid' and 'every' are not universal. Source 2 is the better authority on machine behavior because it documents the RIP settings directly.